Microbial metabolisms directly affect ecosystem functioning and biogeochemical cycles at a global scale. Many microbial taxa have similar potential in how they affect ecosystems' functioning, suggesting a tremendous microbial functional redundancy. It has been hypothesized that redundancy could have crucial roles in ecosystems by: 1) maintaining thei functioning and contributing to their resilience when facing disturbances, 2) improving biogeochemical fluxes via metabolic complementarity. Here, we explore the biological and ecological processes, as well as the technical artifacts that lead to functional redundancy in the ocean’s microbiome. Specifically, we investigate patterns of functional redundancy across methods, spatial and temporal scales, and environments to understand its multi-scale drivers and potential effects on ecosystems. We found that, globally, redundancy in biogeochemical functions was driven by temperature, with lower values in the poles and deep-sea layers. More specifically, redundancy was variable in multiple steps of the Carbon, Nitrogen, and Sulfur cycles with some steps showing low redundancy. The latter points to specific areas of marine metabolic networks that may be particularly vulnerable to global change. Finally, using predictions of environmental conditions and machine learning, we estimate the redundancy of microbial functions in the year 2100 under various climate change scenarios. Our results show that functional redundancy could decrease in polar regions, suggesting that the functioning of these ecosystems could be more vulnerable to disturbances in the future

ASLO Aquatic Sciences Meeting, Resilience and Recovery in Aquatic Systems, 4-9 June 2023, Palma de Mallorca, Spain

Peer reviewed